Circuit interrupting devices, such as ground fault circuit interrupters (“GFCIs”), arc fault circuit interrupters (“AFCIs”), and circuit breakers, have been widely used by consumers since 1970s. Nowadays, due to household safety concerns, there are needs for GFCIs with extra safety features. According to the UL standards under 934A effective Jul. 28, 2006, a GFCI is required not only to have reverse wiring protection, but also to be able to provide a user with indications to alert the user when the GFCI has reached the end of its service life and is no longer capable of providing ground fault protection. That is because for most of the GFCIs currently available on the market, when their service life ends, resetting by pressing the reset button is still possible, which gives the users a false sense of security that they are still under proper protection of the GFCI, while in fact the GFCIs' capability of sensing a ground fault and cutting off the electricity due to a ground fault has been compromised. Thus, when a ground fault occurs, the GFCI is unable to provide any protection, which can result in fatal electric shocks.
The invention to be described in the following sections is a circuit interrupting device which contains an automatic end of life testing system capable of determining whether the major components in the circuit interrupting device function normally without any manual operation of the device when the device is powered on and at a tripped state.